Approximately 20 percent of women wait until their mid- to late 30s to begin having children--a trend attributed to better birth control methods, women in the workforce and couples waiting until they are financially secure before starting a family. Waiting to conceive children is not without risks, however. As a woman ages, so do her eggs. This can make it increasingly difficult for women to get pregnant as they get older.

Fertility

Women reach their peak levels of fertility in their early 20s, when only about 7 percent of females will have trouble conceiving. The infertility gradually gets higher, however, especially after a woman reaches 35 years of age. Between 35 and 39 years old, 22 percent of women are considered infertile. By age 40, the infertility rate rises to 29 percent.

The Female Eggs

Unlike men, who produce new sperm throughout their lives, women are born with all of the eggs they will ever have. This means that a woman's eggs are subject to aging and will eventually be too old to result in a viable pregnancy.

Misconceptions

Although infertility treatments can help many women get pregnant, the chances of conceiving a child are actually the same whether it is done naturally or through the use of assisted reproductive technologies (ART). According to the American Society of Reproductive Medicine, age also affects a woman's ability to respond to fertility treatments, making it increasingly more difficult for women to become pregnant as they get older, regardless of the method.

Risk Factors

Women over the age of 35 who do manage to get pregnant will face a few risk factors because of their age. Miscarriage rates are higher for these women because the age of their eggs makes them less likely to result in a viable pregnancy. In pregnancies that are successful, there is an increased risk of the child developing Down Syndrome.

Male Fertility

Although more pronounced in females, males also experience a decline in fertility as they age. Older men produce lower quantities of sperm, making it more difficult for them to conceive a child naturally. Sperm in older men is also more likely to carry genetic defects.

Source:

American Society for Reproductive Medicine: Age and Fertility